He's just been booked to appear in the Marc by Marc Jacobs advertising campaign and can be seen alongside Karolina Kurkova for Jean Paul Gaultier. So far, he's been photographed by Steven Meisel - the model-maker - and Mert Alas and Marcus Piggott for French and Italian Vogues.

Pejic is part of a movement in fashion to blur gender boundaries. And it's not just about boys who look like girls. Lea T, 28, is a transsexual model booking all the best campaigns fashion has to offer right now.

Part of T's agreement to appear in Givenchy's fall advertising campaign was that she was allowed to talk about her transgender status. When the images appeared in May her modelling agency, Women, was overwhelmed with 400 requests to interview her.

It was Givenchy creative director Riccardo Tisci's idea to have T in the campaign; she has been working at the fashion house since she was 17 as a fit model.

"When you are a transsexual, you look for your future, and you can't see it," T told the New York Times in a recent interview. "I thought this would be a nice message for another tranny: 'Look, we can be the same as other girls and boys.' It's small, but it makes you feel like you have a little chance. Maybe a transsexual will open a magazine and think: 'That's cool. We can be whatever we want.' That's why I did the Givenchy campaign."

Marc Jacobs himself recently appeared on the cover of
Industrie
magazine in drag. Ditto, James Franco for Candy magazine - the first fashion magazine devoted to transgender issues.

Cator Sparks, revered New York men's fashion journalist, dandy and all-around fashion plate has been known to dress in drag "back in the day", he says.

"This current trend of the lumberjack manly man has been done to death," he says. "Now going back to the aesthetic epitomised by the Calvin Klein One campaign, with lots of androgynous models, is a breath of fresh, ambiguous air.

"Jenny Shimizu [the model Angelina Jolie was rumoured to have an affair with] was in a lot of campaigns in the 1990s. No one could tell whether she was a man or a woman. Who cared?

"And to be more philosophical about it, we are growing as a people and as races and as cultures, it's OK to not care what your gender is as long as you look great in clothes."

But, of course, nothing in fashion is ever completely new. Todd Oldham used to use transvestite Billy Beyond in his fashion shows. Joey Arias, also a transvestite, modelled frequently for Thierry Mugler in the late 1980s and is still a fashion muse.

In the 1960s, April Ashley modelled for British Vogue and was photographed by David Bailey and Lord Snowden before her transsexual status was revealed in the tabloid press. Back then, it killed her career.

Then there was Candy Darling, who became an actress and muse to Andy Warhol and, a decade later, transgender model and muse to Stephen Sprouse, Teri Toye. The "It" girl of the 1990s was Connie Girl, also a transsexual.

"The only thing I am irritated about with the current trannies, is that they are not camp enough," says Sparks. "If you are going to be a gender bending femme fatale, come on give me some fake eyelashes and red glitter lips!

"I think every man should wear a pair of high heels once in his life. We have to know how the other half lives."